The aim of this project is to elucidate possible patho-physiological implications of the transamidase-catalyzed cross-linking of membrane proteins which occurs when the intracellular concentration of Ca ion is raised in intact human erythrocytes. Research objectives also include standardization of the assay, isolation and regulation of the erythrocyte transamidase, an investigation of constituent membrane protein participation in forming gamma-glutamyl-episilon-lysine bridges by the intrinsic, Ca2 ion-dependent enzymatic event.